I have a 2006 Hyundai Elantra (Im not sure about engine size, but ~122,000 miles). Recently my check engine light came on. I had it checked and found out that I needed a new catalytic converter. However, the mechanic said I didn't have to necessarily have it replaced right then and there. He said ultimately the check engine light will come if the catalytic converter is not operating according the manufacturer's operation standard (ie the manufacturer's standards may be 99% and if it falls below the check engine light comes on). I would however have to have it fixed before my inspection. So I was wondering how long would I have before the catalytic converter goes bad? What are the symptoms of a catalytic converter going bad. I been riding around with the check engine light on for about few weeks now. One day it will come on, another day it will go off. Would someone offer some insight? Thanks so much for your help. Another question, is it better to have it replaced by the dealership or will any good work?

Recently my check engine light came on. I had it checked and found out that I needed a new catalytic converter

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So I was wondering how long would I have before the catalytic converter goes bad? What are the symptoms of a catalytic converter going bad. I been riding around with the check engine light on for about few weeks now.

Sounds to me like you're already there.

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We offer help in answering questions, clarifying things or giving advice but we are not a substitute for an on-site inspection by a professional.

So the way the the mechanic described it to me was that each manufacturer has a certain performance standard; lets say fore example 98%. He said that just because the catalytic converter is not operating a 98% performance standard, does not necessarily mean that its bad. It could be operating at 97%, which would cause the check engine light to come on. He stated I could ride around with the check engine light on for a while, but ultimate have to have it replaced before inspection.

That's a bunch of bull. Emission standards are Federal. The government mandates that the computer monitor the efficiency of the converter and will set a code when it is no longer doing the job it was designed to. You cannot pass inspection if you have a cat code.

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We offer help in answering questions, clarifying things or giving advice but we are not a substitute for an on-site inspection by a professional.

I know that I cant pass my inspection. I guess what I wondering is how long can I wait before replacing it (Inspection is not until June). Does it have to be replaced now? If I dont replace now, will it cause further damage to some other part of my car?